>> reporter: john mutter teaches environmental science at colombia university. >> what's happening is that if the world is warmer overall, the area that's occupied by the tropics will get larger. so if the tropics expand, they'll bring with them their tropical weather which includes hurricanes. so imagine that now we had ten hurricanes per year and two of them are really monsters. in the future, the expectation is there will still be ten but four of them will be monsters. >> reporter: there may be plenty of legitimate scientific disagreements and plenty of nasty bickering online about how much climate change we're seeing now. but the really frightening part is what's coming. >> i can actually show you temperature over centuries. >> reporter: beth russell runs a n.o.a.a. exhibit called science on a sphere which can present massive amounts of temperature visually. >> here we are in the 1880s, '90s. now in the 1900s. we've seen some changes in temperature through time but really startmy to notice a trend past the year 2000 especially, continuing to step through time, the global is starti